Isotopes
Look at the following groups of atoms. What do you observe?
​
Video 1
Uses of isotopes: isotopes that emit high energy radiation are called radioisotopes which are radioactive.
Did you know that pacemakers were powered by the isotope plutonium-238?
It can kill living cells and cause cancer. If used correctly, it can have important applications
Relative atomic mass
If you look at your Periodic Table, you might have realized that only 1 element in particular has a mass number which is not a whole number. That element is chlorine. Let's find out why it has a relative mass of 35.5.
Video 2
Mass Spectrometry
As to how scientists determine the relative masses of isotopes, they use a mass spectrometer.
This works in three simple steps
1) Vaporise the sample
2) Ionise the sample to give the atoms a charge
3) Pass the ions through a magnetic field.
​
Based on how 'heavy' the ion is, the ion will then deflect wider or closer in a circular path and reach a detector. This detector will measure the number of atoms with the same mass per unit charge (m/e) and show the proportion accordingly.
​
Click on the two images below to learn more on mass spectrometry.
​
​
Did you know?
While isotopes of the same element can undergo similar reactions to form compounds of similar formula, their physical properties are totally different!
For example: hydrogen and deuterium, the story of water and heavy water....
Hydrogen burns in oxygen to form water 2H2(g) + O2(g) → 2H2O(l )
Deuterium (isotope of hydrogen with relative atomic mass of 2) burns to form a similar compound, D2O
​
However, D2O is known as heavy water and while normal ice cubes made from H2O float (beaker on left), solid D2O can sink in water (beaker on the right).
​
One use of D2O is in nuclear plants and you read more on it via this link.
​
Is it safe to drink D2O? Well... do not as your body cannot handle the absorption well. Read more via this link.
​
"The power of the sun, in the palm of my hand" - Dr Ock... Fiction? You better think again. Some movies are often based of reality, in this case, nuclear power with hydrogen isotopes as seen in this article: Milestone Nuclear Fusion milestone
